János Móczó - Academia.edu (original) (raw)

Papers by János Móczó

Research paper thumbnail of Szabályozott méretű, illetve nano részecskékkel társított polimerek előállítása és vizsgálata: adhézió, módosítás, deformációs mechanizmusok = Preparation and study of polymers combined with nanoparticles or fillers of controlled particle size: adhesion, modification, deformation mechanisms

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Research paper thumbnail of Modification of interfacial adhesion with a functionalized polymer in PLA/wood composites

European Polymer Journal, 2015

ABSTRACT Maleic anhydride (MA) grafted poly(lactic acid) (PLA) coupling agents (MAPLA) were prepa... more ABSTRACT Maleic anhydride (MA) grafted poly(lactic acid) (PLA) coupling agents (MAPLA) were prepared by reactive processing. The amount of peroxide initiator and MA was varied over a relatively wide range. Coupling efficiency was checked in PLA/wood composites as a function of grafting degree, coupling agent and wood content. The analysis of the results showed that chain scission takes place in PLA during reactive modification. The occurrence of grafting could not be proved by FTIR spectroscopy, but a detailed NMR analysis showed that the degree of grafting depends on the amount of both reactants; a maximum of 2.5 MA groups/PLA chain could be grafted under the conditions used in the study. The functionalized polymer proved to be an efficient coupling agent in PLA/wood composites. Efficiency increased with increasing number of functionality and coupling agent amount. Coupling resulted in increased strength and reinforcement. Acoustic emission analysis of deformation processes supported by microscopy proved that the dominating local deformation process is the fracture of the fibers, but a small extent of debonding also occurs in neat, uncoupled composites. The prevention of debonding by coupling resulted in the improved performance of the composites. Local processes initiate the immediate failure of the composite irrespectively of their mechanism.

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Research paper thumbnail of Wood fiber reinforced multicomponent, multiphase PP composites: Structure, properties, failure mechanism

Composites Science and Technology, 2014

ABSTRACT

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Research paper thumbnail of Factors determining the performance of thermoplastic polymer/wood composites; the limiting role of fiber fracture

Materials & Design, 2014

ABSTRACT Thermoplastic polymer/lignocellulosic fiber composites were prepared with a considerable... more ABSTRACT Thermoplastic polymer/lignocellulosic fiber composites were prepared with a considerable range of matrices and fibers in an internal mixer. Tensile properties were determined on bars cut from compression molded plates. Local deformation processes initiated around the fibers were followed by acoustic emission testing supported by electron and polarization optical microscopy. The analysis of results proved that micromechanical deformation processes initiated by the fibers determine the performance of the composites. Debonding usually leads to the decrease of composite strength, but decreasing strength is not always associated with poor adhesion and debonding. The direction of property change with increasing wood content depends on component properties and interfacial adhesion. Good interfacial adhesion often results in the fracture of the fibers. Depending on their size and aspect ratio, fibers may fracture parallel or perpendicular to their axis. At good adhesion, the maximum strength achieved for a particular polymer/wood pair depends on the inherent strength of the fibers, which is larger for perpendicular than parallel fracture. Inherent fiber strength effective in a composite depends also on particle size, larger particles fail at smaller stress, because of the larger number of possible flaws in them. A very close correlation exists between the initiation stress of the dominating local deformation process and composite strength proving that these processes lead to the failure of the composite and determine its performance.

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Research paper thumbnail of Polymer/Wood Composites

Wiley Encyclopedia of Composites, 2011

ABSTRACT

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Research paper thumbnail of Adsorption of surfactants on CaCO3 and its effect on surface free energy

Progress in Colloid and Polymer Science, 2004

ABSTRACT

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Research paper thumbnail of Factors affecting the properties of PLA/CaSO 4 composites: Homogeneity and interactions

Express Polymer Letters, 2009

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Research paper thumbnail of Wood flour filled PP composites: adhesion, deformation, failure

Polymers for Advanced Technologies, 2006

Abstract Poly (propylene)(PP) wood composites were prepared in a wide composition range from 0 to... more Abstract Poly (propylene)(PP) wood composites were prepared in a wide composition range from 0 to 70 wt% wood content. Matrix/wood adhesion was improved by the introduction of two maleinated polypropylenes (MAPPs) with different molecular weights and functionality ...

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Research paper thumbnail of Wood flour filled polypropylene composites: Interfacial adhesion and micromechanical deformations

Polymer Engineering & Science, 2007

ABSTRACT

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Research paper thumbnail of Micromechanical deformation processes in PA/layered silicate nanocomposites: Correlation of structure and properties

Polymer Engineering & Science, 2007

... According to the results of XRD measurements (Fig. 2), the silicate modified with the ali-pha... more ... According to the results of XRD measurements (Fig. 2), the silicate modified with the ali-phatic amine exfoliates in a larger extent than the one organophilized with the amino acid, and TEM micro-graphs also indicate considerable exfoliation. ...

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Research paper thumbnail of Effect of desiccant characteristics on the properties of PS/zeolite functional packaging materials

Polymer Composites, 2014

ABSTRACT

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Research paper thumbnail of Filler/matrix-debonding and micro-mechanisms of deformation in particulate filled polypropylene composites under tension

Polymer, 2010

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Research paper thumbnail of Morphology and Properties of Particulate Filled Polymers

Macromolecular Symposia, 2004

ABSTRACT

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Research paper thumbnail of Aggregation of particulate fillers: factors, determination, properties

Macromolecular Symposia, 2003

... 194,111-124 (2003) 111 Aggregation of Particulate Fillers: Factors, Determination, Properties... more ... 194,111-124 (2003) 111 Aggregation of Particulate Fillers: Factors, Determination, Properties Jónos Móczó12, Erika Fekete1'2, Krisztina Làszló3, Béla Pukánszky12* 'institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, H-1525 Budapest ... Vörös, В ...

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Research paper thumbnail of Effect of Clay Modification on the Mechanism of Local Deformations in PA6 Nanocomposites

Macromolecular Materials and Engineering, 2013

ABSTRACT AbstractPA nanocomposites are prepared from clays organophilized with a phosphonium and ... more ABSTRACT AbstractPA nanocomposites are prepared from clays organophilized with a phosphonium and an ammonium salt, and sodium montmorillonite is used as reference. The analysis of mechanical and micromechanical properties of the composites reveal that several micromechanical deformation processes occur in the PA/MMT composites. The matrix cavitates at relatively small stress. Processes related to non‐exfoliated clay structural units are initiated at larger stresses. Sound is emitted mainly by the fracture of particles, but debonding may also occur. The plastic deformation of the matrix dominates at larger stresses and deformations. The various local deformations are independent of each other and composite properties are not determined by silicate related processes but by the deformation of the matrix.

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Research paper thumbnail of Polymer micro and nanocomposites: Structure, interactions, properties

Journal of Industrial and Engineering Chemistry, 2008

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Research paper thumbnail of Determination of the surface characteristics of particulate fillers by inverse gas chromatography at infinite dilution: a critical approach

Journal of Colloid and Interface Science, 2004

CaCO3 fillers were investigated by inverse gas chromatography (IGC) to determine the dispersion c... more CaCO3 fillers were investigated by inverse gas chromatography (IGC) to determine the dispersion component of their surface tension as well as their acid-base character. Because of the high energy of the filler surface, it readily adsorbs water, thus the parameters measured by IGC depend on the conditioning temperature, as well as on the measurement conditions. As a consequence, the determined surface characteristics are not material constants; different fillers or the effect of coating can be compared only under standard conditions. The use of the same conditioning and measurement temperature eliminates the effect of measurement time. Under appropriate standard conditions the acid-base characteristics of the filler can be determined reliably. However, the accuracy of the determination and the value of the derived parameters depend very much on the selected approach and on the acid-base constants used for the probe molecules. A critical analysis of the approaches used in the current literature pointed out those that yield the most reasonable and accurate values. The results prove that the surface of CaCO3 is strongly basic in character. Coating significantly reduces basicity. Surprisingly, the filler coated with an amount of stearic acid resulting in minimum surface tension showed relatively strong acidity, which indicates a coating exceeding monolayer coverage and/or the uneven distribution of the surfactant on the surface.

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Research paper thumbnail of PLA/lignocellulosic fiber composites: Particle characteristics, interfacial adhesion, and failure mechanism

Journal of Applied Polymer Science, 2014

ABSTRACT

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Research paper thumbnail of Acid-Base Interactions and Interphase Formation in Particulate-Filled Polymers

The Journal of Adhesion, 2002

Particulate-filled composites were prepared from CaCO 3 and polymer matrices of various acid-base... more Particulate-filled composites were prepared from CaCO 3 and polymer matrices of various acid-base characters. Interfacial interaction of the components was characterized by the reversible work of adhesion, which was calculated either from dipole-dipole or acid-base interactions. The thickness of the spontaneously formed interlayer was derived from the tensile strength of the composites. The results proved that acid-base interactions play an

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Research paper thumbnail of Analysis of the debonding process in polypropylene model composites

European Polymer Journal, 2005

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Research paper thumbnail of Szabályozott méretű, illetve nano részecskékkel társított polimerek előállítása és vizsgálata: adhézió, módosítás, deformációs mechanizmusok = Preparation and study of polymers combined with nanoparticles or fillers of controlled particle size: adhesion, modification, deformation mechanisms

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Research paper thumbnail of Modification of interfacial adhesion with a functionalized polymer in PLA/wood composites

European Polymer Journal, 2015

ABSTRACT Maleic anhydride (MA) grafted poly(lactic acid) (PLA) coupling agents (MAPLA) were prepa... more ABSTRACT Maleic anhydride (MA) grafted poly(lactic acid) (PLA) coupling agents (MAPLA) were prepared by reactive processing. The amount of peroxide initiator and MA was varied over a relatively wide range. Coupling efficiency was checked in PLA/wood composites as a function of grafting degree, coupling agent and wood content. The analysis of the results showed that chain scission takes place in PLA during reactive modification. The occurrence of grafting could not be proved by FTIR spectroscopy, but a detailed NMR analysis showed that the degree of grafting depends on the amount of both reactants; a maximum of 2.5 MA groups/PLA chain could be grafted under the conditions used in the study. The functionalized polymer proved to be an efficient coupling agent in PLA/wood composites. Efficiency increased with increasing number of functionality and coupling agent amount. Coupling resulted in increased strength and reinforcement. Acoustic emission analysis of deformation processes supported by microscopy proved that the dominating local deformation process is the fracture of the fibers, but a small extent of debonding also occurs in neat, uncoupled composites. The prevention of debonding by coupling resulted in the improved performance of the composites. Local processes initiate the immediate failure of the composite irrespectively of their mechanism.

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Research paper thumbnail of Wood fiber reinforced multicomponent, multiphase PP composites: Structure, properties, failure mechanism

Composites Science and Technology, 2014

ABSTRACT

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Research paper thumbnail of Factors determining the performance of thermoplastic polymer/wood composites; the limiting role of fiber fracture

Materials & Design, 2014

ABSTRACT Thermoplastic polymer/lignocellulosic fiber composites were prepared with a considerable... more ABSTRACT Thermoplastic polymer/lignocellulosic fiber composites were prepared with a considerable range of matrices and fibers in an internal mixer. Tensile properties were determined on bars cut from compression molded plates. Local deformation processes initiated around the fibers were followed by acoustic emission testing supported by electron and polarization optical microscopy. The analysis of results proved that micromechanical deformation processes initiated by the fibers determine the performance of the composites. Debonding usually leads to the decrease of composite strength, but decreasing strength is not always associated with poor adhesion and debonding. The direction of property change with increasing wood content depends on component properties and interfacial adhesion. Good interfacial adhesion often results in the fracture of the fibers. Depending on their size and aspect ratio, fibers may fracture parallel or perpendicular to their axis. At good adhesion, the maximum strength achieved for a particular polymer/wood pair depends on the inherent strength of the fibers, which is larger for perpendicular than parallel fracture. Inherent fiber strength effective in a composite depends also on particle size, larger particles fail at smaller stress, because of the larger number of possible flaws in them. A very close correlation exists between the initiation stress of the dominating local deformation process and composite strength proving that these processes lead to the failure of the composite and determine its performance.

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Research paper thumbnail of Polymer/Wood Composites

Wiley Encyclopedia of Composites, 2011

ABSTRACT

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Research paper thumbnail of Adsorption of surfactants on CaCO3 and its effect on surface free energy

Progress in Colloid and Polymer Science, 2004

ABSTRACT

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Research paper thumbnail of Factors affecting the properties of PLA/CaSO 4 composites: Homogeneity and interactions

Express Polymer Letters, 2009

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Research paper thumbnail of Wood flour filled PP composites: adhesion, deformation, failure

Polymers for Advanced Technologies, 2006

Abstract Poly (propylene)(PP) wood composites were prepared in a wide composition range from 0 to... more Abstract Poly (propylene)(PP) wood composites were prepared in a wide composition range from 0 to 70 wt% wood content. Matrix/wood adhesion was improved by the introduction of two maleinated polypropylenes (MAPPs) with different molecular weights and functionality ...

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Research paper thumbnail of Wood flour filled polypropylene composites: Interfacial adhesion and micromechanical deformations

Polymer Engineering & Science, 2007

ABSTRACT

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Research paper thumbnail of Micromechanical deformation processes in PA/layered silicate nanocomposites: Correlation of structure and properties

Polymer Engineering & Science, 2007

... According to the results of XRD measurements (Fig. 2), the silicate modified with the ali-pha... more ... According to the results of XRD measurements (Fig. 2), the silicate modified with the ali-phatic amine exfoliates in a larger extent than the one organophilized with the amino acid, and TEM micro-graphs also indicate considerable exfoliation. ...

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Research paper thumbnail of Effect of desiccant characteristics on the properties of PS/zeolite functional packaging materials

Polymer Composites, 2014

ABSTRACT

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Research paper thumbnail of Filler/matrix-debonding and micro-mechanisms of deformation in particulate filled polypropylene composites under tension

Polymer, 2010

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Research paper thumbnail of Morphology and Properties of Particulate Filled Polymers

Macromolecular Symposia, 2004

ABSTRACT

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Research paper thumbnail of Aggregation of particulate fillers: factors, determination, properties

Macromolecular Symposia, 2003

... 194,111-124 (2003) 111 Aggregation of Particulate Fillers: Factors, Determination, Properties... more ... 194,111-124 (2003) 111 Aggregation of Particulate Fillers: Factors, Determination, Properties Jónos Móczó12, Erika Fekete1'2, Krisztina Làszló3, Béla Pukánszky12* 'institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, H-1525 Budapest ... Vörös, В ...

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Research paper thumbnail of Effect of Clay Modification on the Mechanism of Local Deformations in PA6 Nanocomposites

Macromolecular Materials and Engineering, 2013

ABSTRACT AbstractPA nanocomposites are prepared from clays organophilized with a phosphonium and ... more ABSTRACT AbstractPA nanocomposites are prepared from clays organophilized with a phosphonium and an ammonium salt, and sodium montmorillonite is used as reference. The analysis of mechanical and micromechanical properties of the composites reveal that several micromechanical deformation processes occur in the PA/MMT composites. The matrix cavitates at relatively small stress. Processes related to non‐exfoliated clay structural units are initiated at larger stresses. Sound is emitted mainly by the fracture of particles, but debonding may also occur. The plastic deformation of the matrix dominates at larger stresses and deformations. The various local deformations are independent of each other and composite properties are not determined by silicate related processes but by the deformation of the matrix.

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Research paper thumbnail of Polymer micro and nanocomposites: Structure, interactions, properties

Journal of Industrial and Engineering Chemistry, 2008

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Research paper thumbnail of Determination of the surface characteristics of particulate fillers by inverse gas chromatography at infinite dilution: a critical approach

Journal of Colloid and Interface Science, 2004

CaCO3 fillers were investigated by inverse gas chromatography (IGC) to determine the dispersion c... more CaCO3 fillers were investigated by inverse gas chromatography (IGC) to determine the dispersion component of their surface tension as well as their acid-base character. Because of the high energy of the filler surface, it readily adsorbs water, thus the parameters measured by IGC depend on the conditioning temperature, as well as on the measurement conditions. As a consequence, the determined surface characteristics are not material constants; different fillers or the effect of coating can be compared only under standard conditions. The use of the same conditioning and measurement temperature eliminates the effect of measurement time. Under appropriate standard conditions the acid-base characteristics of the filler can be determined reliably. However, the accuracy of the determination and the value of the derived parameters depend very much on the selected approach and on the acid-base constants used for the probe molecules. A critical analysis of the approaches used in the current literature pointed out those that yield the most reasonable and accurate values. The results prove that the surface of CaCO3 is strongly basic in character. Coating significantly reduces basicity. Surprisingly, the filler coated with an amount of stearic acid resulting in minimum surface tension showed relatively strong acidity, which indicates a coating exceeding monolayer coverage and/or the uneven distribution of the surfactant on the surface.

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Research paper thumbnail of PLA/lignocellulosic fiber composites: Particle characteristics, interfacial adhesion, and failure mechanism

Journal of Applied Polymer Science, 2014

ABSTRACT

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Research paper thumbnail of Acid-Base Interactions and Interphase Formation in Particulate-Filled Polymers

The Journal of Adhesion, 2002

Particulate-filled composites were prepared from CaCO 3 and polymer matrices of various acid-base... more Particulate-filled composites were prepared from CaCO 3 and polymer matrices of various acid-base characters. Interfacial interaction of the components was characterized by the reversible work of adhesion, which was calculated either from dipole-dipole or acid-base interactions. The thickness of the spontaneously formed interlayer was derived from the tensile strength of the composites. The results proved that acid-base interactions play an

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Research paper thumbnail of Analysis of the debonding process in polypropylene model composites

European Polymer Journal, 2005

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